Cat5 To Rj12 Wiring Diagram - Premium, long lasting tool cuts, strips and crimps. Pass-Thru technology significantly reduces prep work time; tool wiring diagram on tool helps eliminate rework and wasted materials. Compact, non-slip. The Phone Company had to make "ring voltage," normally 90VAC at 20 cycles, using special Ringing Voltage Generators. A regular electric motor drove a magneto (similar to the ones that were cranked by hand on phones), to provide ringing voltage..